Ultraviolet light absorbing compositions



2,95,986 Patented Aug. 30, 1960 tent 551$ ultraviolet light radiation. These compounds can also be used to prepare suntan lotions and creams. 2,950,986 The compounds suitable for use in the preparation of the ultraviolet light absorbing compositions and composite 5 articles of this invention are the silicon-containing amine salts of the benzophenone sulfonic acids. These com- Donald L. Bailey, Snyder, and Ronald M. Pike, Grand pounds and the processes for their production are the sub- Island, N.Y., assignors to Union Carbide Corporation, ject matter of our co-pending patent application, Serial a corporation Of New York No. 615,495, filed October 12, 1956. The compounds are produced by the reaction of an aminoalkylsilane or No Dmwmg' Filed 1957 679739 an aminoalkylsiloxane with an unsubstituted or substituted Claims. (Cl. 11733.3) benzophenone sulfonic acid as hereinafter described.

The compounds suitable for use as stauting materials in this invention are the monomeric silane amine salts of Thi invention l t t lt iol t light absorbing 15 benzophenone sulfonic acids, which can be represented by compositions. More particularly, it is concerned with The following general formula: new compositions having therein a silicon-containing y El Y benzophenone sulfonic acid derivative as an ultraviolet O m, l' i G 63 i -1ght absorber, and to novel composite articles contain Y soymNcnHhsixm ing said ultraviolet light radiation absorbers.

and the siloxane amine salts of benzophenone sulfonic It is well known that ultraviolet light radiation, which has a wavelength range between about 2500 and 4000 acids, which contain the unit represented by the following general formula:

Angstrom units, has a degradative effect on many com mercial products. It is also well known that these radiations can cause severe skin burning on over-exposure of the human body to sunlight. To cut down on the occur- Y 0 rence of these harmful effects, ultraviolet light absorbers ("I have been added to products which will be exposed to Y I I ultraviolet light such as plastics and the like, and to sunwherein Y and a have the same meanings as hereinbefore tan lotions and creams which are used on the skin.

Among the ultraviolet light absorbers known, there may indicated; R represents a hydrocarbon radical such as an alkyl radical, for example, methyl, ethyl, propyl, and the be mentioned the benzophenones, such as 2,4-dihydroxybenzophenone, Z-hydroxy-4-methoxybenzophenone, 2,2- dihYdYOXY-4,4'-dime1h0XYbeI1Z0PheI10I1, SOdium like, an aryl radical such as phenyl, tolyl, and the like, or hyilfoXybellzophefione 5 sulfoflfltei i di y an aralkyl radical such as benzyl, and the like; X repreamlno) benzophenollfisa The dlnitrodlialkylaminobenzosents an alkoxy radical such as methoxy, ethoxy, and the Phen0I1e$ and the like like, or an aryloxy radical such as phenoxy, and the like; The use Of Ultraviolet light absorbers 011 glass articles I) is an integer having a value of from 1 to 3; and c is an id Protect PTOduCtS on p y behind the glass P integer having a value of from 0 to 2. These compounds, or in the glass container, has not heretofore been possible 40 as di l d i S rial No. 615,495, are produced by the P60211186 of difliculty in Obtaining a Satisfactory reaction of an organosilicon compound containing the mg on glass due to its inertness. The coatings heretofore aminoalkylsilyl group H Nc,,H ,siE with a benzophenone Obtaifled on glass Pmdllcts were temporary in nature, and sulfonic acid, as represented by the following general Could be readily removed y rubbing y Washing with equation, wherein benzophenone-4-sulfonic acid is used soap and water. for illustrative purposes.

It has now been found that silicon-containing benzophenone derivatives having the unit represented by the 0 general formula: ii

HZNC H SiE-i- H SOaH e e 0 Y I b SOS-HQNCBHZQSE wherein Y can represent hydrogen atoms, hydroxyl radicals, alkyl radicals such as methyl, ethyl, propyl, and the like, alkoxy radicals such as methoxy, ethoxy, and the like, nitro radicals, dialkylamino radicals such as dimethylpounds for use as starting materials in producing the amino, diethylamino, and the like; and a is an integer amine salts of the benzophenone sulfonic acids are garnhaving a value of at least 3, and preferably a value of ma-aminopropyltriethoxysilane, delta-aminobutylmethyl- 3 or 4; can be used to produce new compositions which diethoxysilane, gamma-aminopropylmethyldiethoxysilane, are opaque to ultraviolet light. It has been found that gamma aminopropylphenyldiethoxysilane, delta-aminothe ultraviolet light absorbing silicon-containing benzobutyltriethoxysilane, gamma-aminopropyltrimethylsilane, phenones are not readily removed from glass surfaces, delta-aminobutyltriethylsilane, modified dimethyl silicone and can be used to obtain glass articles which are opaque oils containing gamma-aminopropylmethylsiloxy units, to ultraviolet light radiation. It has also been found delta-aminobutylphenylsiloxy units and the like.

that they can be blended into plastic compositions, which Among the benzophenone sulfonic acids suitable for reare thereby stabilized against the degr-adative effect of action with the aminoalkylsilicon compounds in producing More particularly, suitable aminoalkylsilicon comv 3 the amine salts there may be mentioned 2,4-dihydroxybenzophenone-S-sulfonic acid, 4-nitrobenzophenone-Z-sulfonic acid, 4-methyl-benzophenone-2'-sulfonlc acid, 2,4- dimethylbenZophenone-2-sulfonic acid, 2,4-dimethyl-3- nitrobenzophenone sulfonic acid, 4-di1nethylaminobenzophenone sulfonic acid, 2,4-dihydroxybenzophenone-4'- sulfonic acid, and the like. 7

The ultraviolet light absorbing'compositions of this invention comprise a base material in combination with the silicon-containing ultraviolet light absorber, and include solutions, creams, lotions, or solid compositions as ereinafter described. The effectiveness of the compo sition in absorbing ultraviolet light radiations is dependent on the concentration of the silicon-containing amine salt of benzophenone sulfonic acid present in the product to be protected, or upon the thickness of the layer of ultraviolet absorbing silicon-containing amine salt of the benzophenone sulfonic acid deposited on the surface of the film, filament, or other article.

In accordance with this invention, glass panes or bottles can be made opaque to ultraviolet light radiations. This has been accomplished by forming a film of siliconcontaining amine salt of a benzophenone sulfonic acid on the surface of the glass article. The film is produced by coating the glass article with a solution of the ultraviolet light absorber, drying the film on the glass surface, and then curing it by heating at an elevated temperature; whereby a tough, clear film, opaque to ultraviolet light is produced on the surface. In producing the film on the glass article, the glass article is dipped into an aqueous solution, or an organic solvent solution, of the silicon-containing amine salt of a benzophenone sulfonic acid at a bath temperature of from about 25 C. to about 100 C. for a period of at least about one minute. Preferred dipping conditions are at bath temperatures of from about 70 C. to about 85 C. to about 2 minutes since under these conditions the clearest films are obtained' Ordinan'ly bottles and other glass containers are coated on the outside only in order to avoid the possibility of contaminating the product which is to be shipped in the container.

After dipping and drying, the coated glass article is baked at temperatures of at least about 150 C. for a period of at least about 10 minutes. Preferably a temperature of at least about 250 C. is employed in order to satisfactorily bond the film to the glass. Higher temperatures can be used, but care must be exercised that the temperature is not raised so high that degradation of the ultraviolet light absorber takes place. For best results the curing step is preferably carried out at about 250 C. for about minutes, although the film shows no signs of deterioration when heated for about 45 minutes under these conditions. Films baked to glass articles at temperatures above about 225 C. are not readily removed by rubbing or washing with cold water, warm tap water, or cold water containing a soap or detergent.

The concentration of the ultraviolet light absorber in the dipping bath can vary depending on the thickness of the film of ultraviolet light absorber desired on the glass. For example, at a bath concentration of about 0.5% by weight the film on the glass article will be about 4 microns thick, while at a bath concentration of about 2% by weight the film will be about 14 microns thickv Films about microns thick have been found to absorb up to about 98% of the ultraviolet light up to a wavelengthof about 3800 Angstroms. As indicated, the thicker the film, the lower will the percent transmission of ultraviolet light radiation be, and the greater will the absorption be. If desired, the glass may first be sized with a sizing agent, such as vinyltriethoxysilane, to obtain better bonding between the glass and the ultraviolet light absorber.

It is also possible by the processes of this invention to produce plastic articles stable to ultraviolet light radiation, for example, vinyl plastics or polyethylene. In

stabilizing a plastic material to ultraviolet radiation, from about 0.1 to about 2.5 parts by weight of the siliconcontaining amine salt of the benzophenone sulfonic acid can be added to the plastic before it is spun into filaments or extruded into film; or the film, filament, or other plastic article can be coated ,by dipping into a solution of the ultraviolet light absorber and then drying.

When a plastic film, or fibrous material, is coated with the ultraviolet light absorbing compositions, the coated material may be heated, but to a temperature not exceeding the softening point of the plastic. 7 For example, a polyethylene film should not be heated above about 90 C. When the ultraviolet light absorber is blended into a plastic mass, it may be added in the form of a solution and then the solvent evaporated, or the undiluted compound may be added to the heat softened mass and blended in on a Banbury, a two-roll mill, or like apparatus.

In producing the novel suntan lotions of this invention,

a solution of the silicon-containing amine'salt of the benzophenone sulfonic acid in a mixture of organic solvents and oils, or in a solvent-water mixture is prepared. It has been found that the solvents which are conventionally used in producing suntan lotions can be used with the silicon-containing amine salts of the benzophenone sulfonic acids to produce the suntan lotions of this invention. Among the suitable solvents are ethanol, isopropanol, glycerine, propylene glycol laurate, mineral oil, propylene glycol, triethanolamine, and the like, which are conventionally used in preparing lotions. Suntan cream compositions can be produced by adding the ultraviolet light absorber to a cream composition prepared in the conventional manner. Among some of the conventional products used in producing suntan cream compositions are stearic acid, propylene glycol, cetyl alcohol, lanolin, mineral oil, beeswax, triethanolamine, and the like.

The following examples further serve to illustrate this invention. Parts are by weight unless otherwise specified.

Example I There was slowly added at 25 C. a solution of 0.71 part of gamma-aminopropyltriethoxysilane, 0.0135 part of triethylamine and 14.25 parts of water to a solution of 0.7 part of 2,4-dihydroxybenZophenone-4'-sulfonic acid in 14.25 parts of water. The reaction which occurred was exothermic and clear yellow solution was produced, which contained the siloxane salt having units represented by the following structural formula:

The clear yellow solution of the above-indicated siloxane salt was diluted with water to a total volume of 60 m1. and then heated to about 75 C. A glass slide, which had been washed in hydrochloric acid and then rinsed with distilled water, was immersed in the solution at 75 C.'

for 2 minutes. The slide was removed, air dried and heated in an oven at 250 C. for 15 minutes to cure. A slightly yellow, clear film, about 7 microns thick on each side, was formed on the slide. This slide is hereinafter designated slide A. I

The diluted siloxane salt solution used to coat slide A was further diluted to a total Volume of ml. This latter solution was used to coat another glass slide by the same procedure used to coat slide A. A film about 6 microns thick on each side thereof was produced on the second slide. This second slide is hereinafter designated slide B.

The percent transmission of ultraviolet light radiation Jill of both of the above-prepared coated slides was found to be as follows:

Percent Transmission Wavelength, Angstrom Units Slide A Slide B Example 11 Delta-aminobutylmethyldiethoxysilane and 2,4-dihydroxybenzophenone-4-sulfonic acid were reacted by the procedure described in Example I to produce a solution of the siloxane salt containing units which can be represented by the following structural formula:

Wavelength, Angstrom units: Percent transmission Example 111 There was charged 20 grams of copolymer containing parts of combined gamma-aminopropylmethylsiloxy units per 100 patrs of the copolymer to a 150 ml. beaker. This copolymer was a colorless silicon oil, which contained mostly combined dimethylsiloxy units in addition to the combined gamma-aminopropylmethylsiloxy units and had an average molecular Weight of about 5000. T 0 this copolymer there was added, at about 25 C., 2.47 parts of 2,4-dihydroxybenzophenone-4sulfonic acid While continuously stirring the reaction mixture. During the addition the silicone oil became light yellow in color, and very viscous. The viscosity of the reaction mixture was decreased by the addition of 20 ml. of toluene to the mixture. After all of the 2,4-dihydroxybenzophenone 4-sulfonic acid had been added, the clear, light yellow solution was filtered and the filtrate was concentrated under reduced pressure leaving a. light yellow viscous residue weighing 18 g. The residue was an excellent ultraviolet light absorber, showing absorption at wavelengths of from about 2200 to about 3200 Angstroms, and can be represented by the following structural formula:

in r tr 1 OH Jea. 2.5 Example IV A solution of 0.83 part of 2,4-dihydroxybenzophenone- 4'-sulfonic acid in 20 ml. of water was slowly added to a solution of 1.17 parts of gamma-aminopropylmethyldiethoxysilane in 20 ml. of water. A slightly exothermic reaction occured and a clear, light yellow solution of the amine salt resulted. Added 40 ml. of water to the mixture and the solution was stirred.

A glass slide coated with this formulation, as described in Example I, showed good ultraviolet light absorbing properties up to a Wavelength of about 3300 Angstrom units.

Wavelength, Angstrom units Percent transmission Example V A suntan lotion was produced by adding 0.83 part of 2,4-dihydroxybenzophenone-4-sulfonic acid to a stirred solution of 1.17 parts of gamma-aminopropylmethyldiethoxysilane, 10 parts of glycerine, 10 parts of propylene glycol laurate, parts of ethanol and 13 parts of water. The lotion was a clear, light yellow solution containing siloxane units represented by the general formula:

This suntan lotion showed good ultraviolet light absorption properties when tested in a 1 cm. cell at a concentration of 3.812 g./l. in absolute ethanol; results are tabulated below:

Wavelength, Angstrom units Percent transmission What is claimed is: 1. An improved ultraviolet light absorbing composition comprising a base material and a silicon-containing 7 amine salt of a benzophenone sulfonic acid containing the unit reprmented by the general formula: a

Y (H) Y e e Y SOQ-HBNGBHZDSIE wherein Y represents a member selected from the group consisting of hydrogen atoms, hydroxyl radicals, alkyl radicals, allroxy radicals, nitro radicals, and dialkylamino radicals; and a is an integer having a value of at least 3.

2. An improved ultraviolet light absorbing composition as claimed in claim 1 wherein the base member is a glass article.

3. An improved ultraviolet light absorbing composition as claimed in claim 1 wherein the base member is a plastic article.

4. An improved ultraviolet light absorbing composition comprising a base material and a silicon-containing amine salt of a benzophenone sultonic acid selected from the group of silane amine salts represented by the general formula:

b C e e S O3-H3N C HnSiXs-r,

wherein Y represents a member selected from the group consisting of hydrogen atoms, hydroxyl radicals, alkyl radicals, alkoxy radicals, nitro radicals, and dialkylamino radicals; R represents a member selected from the group consisting of hydrocarbon radicals; X represents a member selected from the group consisting of alkoxy radicals, and aryloxy radicals; a is an integer having a value of at least 3; and b is an integer having a value of from 1 to 3.

5. An improved ultraviolet light absorbing composition comprising a base material and a siloxane of a siliconcontaining amine salt of a benzophenone sulfonic acid selected from the group of siloxanes containing the unit represented by the general formula:

wherein Y represents a member selected from the group consisting of hydrogen atoms, hydroxyl radicals, alkyl radicals, alkoXy radicals, nitro radicals, and dialkylamino radicals; R represents a member selected from the group consisting of hydrocarbon radicals; a is an integer having a value of atleast 3; and c is an integer having a value offromOto 2. a

6. An improved ultraviolet light absorbing composition as claimed in claim 4, wherein the base material is a glass article.

7. An improved ultraviolet light absorbing composition as claimed in claim 5, wherein the base material is a glass article. I

8. An improved composition of matter comprising a plastic article and a stabilizing amount, sufficient to stabilize the plastic against ultraviolet light degradation, of a silicon-containing amine salt of a benzophenone sulfonic acid selected from the group of silane amine salts represented by the general formula:

(g Y Ym msanfio ,nhiizih,

wherein Y represents a member selected from the group 8 consisting of hydrogen atoms, hydroxylradicals alkyl radicals, alkoxy radicals, nitro radicals, and dialkylamino radicals; R represents a member selected from the group consisting of hydrocarbon radicals; X represents a member selected from the group consisting of alkoxy radicals,

'and aryloxy radicals; a is an integer having a value of at least 3; and b is an integer having a value of from 1 to 3. 9. An improved composition of matter comprising a plastic article and a stabilizing amount, sufficient to stabilize the plastic against ultraviolet light degradation, of a siloxane of a silicon-containing amine sale of a benzophenone sulfonic acid selected fro rn the group consisting of siloxane amine salts containing the unit represented by the general formula: V V V v 7 i ter comprising a glass base material and a film thereon of a siloxane containing unit represented by the general formula:

9 ea no SOs-HuN(CH2)sSiO3/2 g 11. An ultraviolet light absorbing composition of matter comprising a glass base material and a film thereon of a siloxane containing the unit represented by the general formula:

12. An ultraviolet light absorbing composition of matter comprising a glass base material and a film thereon of a siloxane copolymer containing units represented by the following formula:

1 an t SiO SiO J L OHLL (9311:)?

GBNHa G I [(CHa)aSiO [Si(CHa)s] wherein x is an integer.

13. A process for producing glass articles opaque to ultraviolet light radiation, which comprises coating the surface of said glass article on at least one side thereof with a silicon-containing amine salt of a benzophenone sulfonic acid containing the unit represented by the general formula:

Y Y 13 e e Y soyHsNo H sE wherein Y, a and b have the same meanings as claimed in claim 4, and heating said coated glass article at a temperature of at least about 150 C. for a period of at least about minutes.

15. A process for producing glass articles opaque to 10 ultraviolet light radiation, which comprises coating the surface of said glass article on at least one side thereof with a siloxane of a silicon-containing amine salt of a benzophenone sulfonic acid selected from the group of siloxanes containing the unit represented by the general formula:

wherein Y, a and 0 have the same meanings as claimed in claim 5, and heating said coated glass article at a temperature of at least about C. for a period of at least about 10 minutes.

References Cited in the file of this patent UNITED STATES PATENTS 2,043,860 Morgan June 9, 1936 2,134,947 Isermann Nov. 1, 1938 2,334,348 Miglarese Nov. 16, 1943 2,686,812 Wynn et a1. Aug. 17, 1954 2,763,566 Van Allan Sept. 18, 1956 OTHER REFERENCES Spier et al.: Jour. Am. Chem. Soc., volume 78 (May 20, 1956), pages 2278-81.

UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,950,986 August 30, 1960 Donald L. Bailey et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, lines 50 to 55, the formula should appear as shown below instead of as in the patent:

Y H Y Y soa-mNomnsia column 5, line 59, for patrs read -parts; line 60 for silicon read -silicone; column 7 lines 45 to 4:9, for the left-hand portion of the formula reading Signed and sealed this 9th day of May 1961.

Attest: ERNEST W. SWIDER, DAVID L. LADD, Attestz'ng Ofiicer. Gammz'ssioner of Patents.

UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,950,986 August 30, 1960 Donald L. Bailey et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, lines 50 to 55, the formula should appear as shown below instead of as in the patent:

Y H Y C 9 63 YO GS Oa-HaNC lHhSiE column 5, line 59, for patrs read parts; line 60 for silicon read silicone; column 7, lines 45 to 49, for the left-hand portion of the formula reading Signed and sealed this 9th day of May 1961.

[SEAL] Attest ERNEST W. STVIDER, DAVID L. LADD, Attestz'ng Oficer. Gammz'ssz'oner of Patents. 

14. A PROCESS FOR PRODUCING GLASS ARTICLES OPAQUE TO ULTRAVIOLET LIGHT RADIATION, WHICH COMPRISES COATING THE SURFACE OF SAID GLASS ARTICLE ON AT LEAST ONE SIDE THEREOF WITH A SILICON-CONTAINING AMINE SALT OF A BENZOPHENONE SULFONIC ACID SELECTED FROM THE GROUP OF SILANE AMINE SALTS REPRESENTED BY THE GENERAL FORMULA: 